Youngsters from south China's Hong Kong visit the Juyongguan Pass of the Great Wall in Beijing, capital of China, July 21, 2019. (Xinhua/Ju Huanzong)

Two young men from south China's Hong Kong take photos at the Juyongguan Pass of the Great Wall in Beijing, capital of China, July 21, 2019. (Xinhua/Ju Huanzong)

Youngsters from south China's Hong Kong pose for a group photo at Juyongguan Pass of the Great Wall in Beijing, capital of China, July 21, 2019. (Xinhua/Ju Huanzong)